You are sort of making the argument for what they op said.

You have time. You are just prioritizing different things.

It seems ok to tell the band director, that it is ok not to practice outside of school because you have sports or other homework.

I did not see anywhere that it was ok to tell the coaches that you would miss sports practice to practice your instrument or do homework.

We can do sports 4 or more days a week but we can't find 20 minutes to practice. REALLY?????